The present invention relates to a perfected hinge for a spectacle mount, and more specifically to a hinge which may be used to advantage to connect the lenses to the ear-pieces (temple assemblies or lateral arms) of a rimless spectacle mount, the elements of which are all or mostly made of highly elastic but permanently deformable wire material, such as metal wire, or of composite synthetic material (e.g. carbon fibers), and which comprises two lateral arms pivoting on respective hinges connected, even indirectly, to the lenses by respective bent wire portions, and a bridge also fitted elastically by bent wire portions to the lenses.
European Patent N. 256.098-B1 relates to a mount for spectacle lenses, made of metal wire and wherein the hinges of the lateral arms are each defined by a fixed straight portion connected to the lens by a bent wire portion and forming the hinge pin, and by a movable portion connected to the lateral arm and defined by a coiled wire portion pivoting about the fixed pin. The free end of the coiled wire portion defines a stop for arresting rotation of the coiled portion, and hence of the lateral arm, by contacting the bent wire portion; and the bent wire portion connecting the straight portion or fixed pin to the lens is bent twice by 90.degree., with the bends in planes perpendicular to each other, and continues towards the lens in the form of a U-shaped bend located in a normally vertical plane parallel to the fixed pin, and which is inserted elastically inside a respective opening formed close to the outer edge of the lens.
After fitting the lateral arm onto the fixed pin, this type of hinge involves mechanically bending the outer end of the pin to prevent withdrawal of the coiled portion, so that the hinge can no longer be broken down into its two component parts for repair or for combining different finish elements after production. Moreover, in the event the lateral arm is forced, e.g. knocked, open beyond its normal travel, the stop defined by the free end of the coiled portion of the lateral arm, and which is a definite obstacle to rotation of the arm, transmits the stress on the arm to the spectacles, thus resulting in serious damage to the mount and lenses. This type of hinge is therefore relatively fragile and complex in design, and it is extremely difficult to achieve precise slackfree mutual rotation of the hinge elements, combined with constant friction which may be adjusted as required over time.